Ultra-low power mesh network

ABSTRACT

A mesh receiver has a wakeup receiver for reception of a wakeup sequence formed by keyed RF or a sequence of wireless packets and gaps, a transmitter forming low speed RF wakeup sequence to other mesh stations, a mesh receiver for reception of high speed WLAN packets, the transmitter sending a wireless ACK packet in response to a wakeup sequence, the mesh receiver thereafter receiving wireless packets from a remote station, the mesh transmitter sending an ACK, the mesh station thereafter identifying a next hop station, and sending a wakeup sequence to that station, after receipt of an ACK, sending the data, the mesh receiver and mesh transmitter thereafter going to sleep.

The present application is a continuation of patent application Ser. No.16/918,342 filed Jul. 1, 2020, which is a continuation of patentapplication Ser. No. 15/811,690 filed Nov. 14, 2017, now issued as U.S.Pat. No. 10,742,429.

FIELD OF THE INVENTION

The present invention relates to stations and methods for providing lowpower connectivity in a mesh network. In particular, the inventionprovides ultra-low power connectivity for stations positioned inreceiving range of each other.

BACKGROUND OF THE INVENTION

Prior art wireless systems such as 802.11 provide communications where acentral node (an “access point”) is coupled to other stations using an“infrastructure mode”. This type of infrastructure system relies on theaccess point being powered continuously, and the power savings comesabout by using, for example, access point beacon frames, where theaccess point periodically transmits beacon frames at expected times,such that the stations wake up at corresponding intervals of time andlisten to beacon TDIM frames which indicate whether packets areavailable at that time of coming out of a sleep mode. The powerconsumption is thereby reduced by a factor equal to the small percentageof time the stations are awake compared to the beacon interval. Thistype of infrastructure works well where the access point is able to bepowered by an external power source, and requires that the stations beclustered within receiving range of the access point. FIG. 1 shows anexample positioning of stations S1 through S8 and access point AP1.Typical attenuation of wireless signals is as follows (2× indicates adoubling of separation distance between stations):

Line of Sight (LOS) loss  6 dB/2x distance Indoor LOS loss withmulti-path 12 dB/2x distance loss per concrete floor traversal 15dB/floor + indoor LOS loss

Accordingly, if the network of FIG. 1A were in open space withoutbarriers and examined in plan view (positioned horizontally in openspace), the loss from AP1 to S1 might be 61 dB, AP1 to S2 67 dB, and AP1to S4 71 dB, whereas for the same dimensions, with FIG. 1A examined asan elevation view with the lines representing concrete floors andincluding indoor multipath loss, the loss from AP1 to S1 would be 106dB, from AP1 to S2 would be 157 dB, and from AP1 to S3 would be inexcess of 200 dB. If the link budget is on the order of 140 dB, thenmost of the stations are out of range of the access point.

Another type of network is known as a mesh network, where the stationseach communicate with each other as peers. For FIG. 1A, this type ofnetwork topology has S1 communicate with AP1 and S2, S2 to S1, S4, S5,and S3, etc. The mesh network has a different set of considerations andissues. One issue is that the network needs to find a route from eachstation to a gateway such as AP1, and another issue is that there is nocentralized timing or transmission as infrastructure mode provides.

Both types of networks, infrastructure and mesh, require access to theinternet at large, which is provided by a function known as a gatewayrouter. This functionality is typically offered through an access pointAP1 of FIG. 1A, or it may alternatively be offered through a meshstation having connectivity to a gateway router.

Battery powered systems utilize a finite amount of Joule stored energy,such that the Joule product of power*time may be conserved only byeither reducing power or reducing the amount of time that power isdrawn. When viewed from the perspective of a fixed Joule source and adesired battery lifetime for a given battery size, the problem reducesto one of duty cycle and latency. In the following illustrations ofprior art, a fixed source of two AAA batteries is used, which provides1000 mAh @3V. Accordingly, for 10 year operation form this storagesource, the average current draw is maximum 10 uA at 3 V, which will nowbe used to compare the performance of various prior art systems.

In the prior art, battery powered network nodes typically use Bluetooth(at a typical 6 mA listen current at 3V) which offers lower powerconsumption than 802.11 WLAN (at a typical 60 mA listen current at 3V).For a 10 year battery life using two AAA batteries, and the best case ofsynchronous wakeup intervals across all stations, an average current of10 uA could be accomplished in Bluetooth (from 5 mA continuous current)by power-cycling the Bluetooth device on for periodic and synchronizedlisten intervals across all stations, with a duty cycle of 1/500 and a 1ms on (listen) time. The corresponding approach could be used in WiFiwith a duty cycle of 1/6000 and a 1 ms on (listen) time, both wouldsatisfy the 10 uA average current requirement specified. The 10 year 1AH 3V constraint using two AA cells is used as a uniform baselineexample for understanding the invention and its benefits, other powersource capacities can be computed using those metrics in the samemanner.

For a mesh of 4 stations, where one station has to check with each ofthe four other stations, each check requiring a 1 ms event wakeup event,the time for each hop is 1 ms*500*4=2s for Bluetooth and 1 ms*6000*4=24sfor WiFi. Accordingly, just 10 hops through a mesh network has a latencyof 20s (˜4 min) for Bluetooth and 4 minutes for WiFi, which areunacceptable for most purposes.

With four edge nodes (reducing throughput by 4), and where WiFi datathroughput is 10 Mbps peak (at 1/6000 duty cycle) and Bluetooththroughput is 250 Kbps (at 1/500 duty cycle), the above examples provideper-day download data of 18 MB for WiFi and 5.4 MB for Bluetooth, whichwould restrict these uses to very low data transfer applications.

Another problem of the prior art is that for dynamically changingnetworks, a significant amount of power is consumed with RF advertising,in the case of Bluetooth (Bluetooth Low Energy, known as BLE), where theslave device has an advertising interval and the master device has ascan window and scan interval. As the below table shows, short Bluetoothconnection times require the advertising window and scan interval bothbe short, which greatly increases battery drain. For Bluetooth LongRange (BLR), the problem is exacerbated over BLE by the increased BLRtransmit frames and requirement for low duty cycle.

Advertising Scan Scan Avg 99% interval Window Interval connectionconnection (ms) (ms) (ms) time (s) time (s) 30 30 30 .02 0.04 60 30 30.03 0.07 100 30 30 .06 0.11 30 11.25 1280 2.71 12.8 60 11.25 1280 5.5423.04 100 11.25 1280 8.92 35.84 1280 30 30 0.67 1.37 1280 11.25 1280162.5 323.84

It is desired to provide an apparatus and method for ultra-low powermesh networks which provides bidirectional connectivity from a pluralityof peer stations to a gateway router at a higher data rate than theprior art provides.

OBJECTS OF THE INVENTION

A first object of the invention is a mesh device and method forreceiving packets, the mesh device having a wakeup receiver and a meshreceiver, the wakeup receiver receiving wakeup frames optionallycomprising a first wakeup segment and a second wakeup segment followedby an optional command part, the wakeup receiver comparing the wakeupsegments against respective patterns, and when the wakeup segments matchthe respective patterns, optionally examining the command part, the meshreceiver thereafter waking up and accepting WLAN packets, the meshreceiver thereafter receiving packets and placing them into a queue,thereafter the mesh receiver sending a wakeup sequence directed to aremote node of the mesh based on a routing destination, the nodetransmitting the packets from the receive queue, thereafter going backinto a sleep mode upon acknowledgement of receipt by the remote node.

A second object of the invention is a mesh device and method fortransmitting packets, the mesh device having a transmitter in a wakeuptransmit mode which transmits an entire packet to form each 1 value andnot transmitting for an equal interval of time to form a 0 value duringa wakeup transmit interval to send a sequence of 1 and 0 values forminga wakeup sequence, after a remote mesh station has awaken in response tothe wakeup sequence and replied with an acknowledgement, thereafter thetransmitter operative in a mesh transmit mode to send WLAN packets andgoing back to sleep when completed.

A third object of the invention is an apparatus and method for ultra-lowpower communications operative on a mesh device having a wakeuptransmitter, the wakeup transmitter periodically transmitting a wakeupsequence of 1s and 0s, where each 1 is formed from the transmission ofan entire WLAN packet, and each 0 is formed by non-transmission duringan interval corresponding to the duration of a WLAN packet, the remotestation acknowledging the wakeup sequence by sending an acknowledgementpacket.

A fourth object of the invention is an apparatus and method for sendinga wakeup sequence to a remote station using a WLAN transmitter, the WLANtransmitter sending a first sequence of is and 0s, each 1 formed from anentire WLAN packet or RF keying and each 0 formed by an interval ofnon-transmission having a duration equal to the duration of a WLANpacket, the WLAN thereafter sending a second sequence of 1s and 0s, each1 formed from an entire WLAN packet or RF keying which is shorter than aWLAN packet or RF keying of the first sequence and each 0 formed by aninterval of non-transmission equal to the duration of a second sequenceWLAN packet.

A fifth object of the invention is an apparatus and method for ultra-lowpower communications operative on a mesh device having a wakeupreceiver, the wakeup receiver operative continuously and operative todetect a first pattern of is and 0s formed from entire WLAN packetsfollowed by a second pattern of is and 0s formed from entire WLANpackets of shorter duration than the WLAN packets of the first pattern,the wake-up receiver operative to listen to the first sequence andsecond sequence, if the first sequence and second sequence matchrespective template patterns, the wakeup receiver next receiving aunicast or broadcast address and an optional command containing achannel assignment or protocol assignment for a receiving mesh node.

SUMMARY OF THE INVENTION

A mesh network node known as “Wake-Fi™” has a transmitter operative in awakeup mode and a mesh transmit mode. In a wakeup transmit mode, thenode periodically transmits a wakeup sequence to surrounding meshnetwork nodes with is either node specific (unicast) or universal(broadcast), the wakeup sequence operative to enable at least onesurrounding mesh network node. The wakeup sequence may also include anoptional command, such as a mesh protocol assignment, which may directsubsequent communications to be using one of the 802.11 WLAN protocols,Bluetooth Low Energy protocol, Bluetooth Long Range protocol, Zigbeeprotocol, or contain a channel hopping assignment, frequency assignmentor channel assignment for use in subsequent communications. The nodetransmits the wakeup pattern as a sequence of a series of 1 and 0 valuesusing a low power RF transmitter to form the wakeup sequence, each 1formed from an entire wireless packet of fixed length, with a singlepacket representing a 1 value, and the absence of transmissionrepresenting a 0 value and of equal duration as the packet of the 1value. The RF generated for the wakeup sequence need not be precisionfrequency or formed from a packet, but simply RF that can be mixed,rectified and detected, such as RF from a ring oscillator or othersimple low power method. The wakeup sequence optionally has a firstunique sequence which is transmitted at a low data rate, and a secondsequence which is transmitted at a comparatively faster data rate.Alternatively, the wakeup sequence may be a unique sequence, matchingthe wakeup pattern for at least one surrounding node. Following theacknowledgement of the wakeup pattern with a wireless packet, thetransmitter may thereafter send WLAN packets for propagation through themesh network.

Each mesh network node also has an ultra-low power receiver which isoperative to receive the wakeup sequence formed from entire packetstransmitted by a different mesh node. Upon receipt of the wakeupsequence and any optional commands which follow, the node wakes up andtransmits an acknowledgement as a WLAN packet in a mesh transmit mode.Upon receiving the matching wakeup pattern, mesh network node powers upa fully-featured receiver and receives and buffers any packets whichfollow, acknowledging reception and powering down until a subsequenttransmit event for sending the packets through the mesh network.

In an advertising mode, each mesh network node sends out a shortperiodic advertisement, which all surrounding stations receive and useto update their connectivity table to indicate the respective powerlevel of the received advertisement.

In a communications mode, when the mesh network node has data totransmit or forward, the mesh node determines which mesh node is alongthe best path, and best receiver, and optionally selects a mesh stationto equalize power consumption or resource utilization using a table ofnearby stations which indicate for each nearby station a signalstrength, hop count to a gateway if applicable, battery state of charge(to ensure uniform draw on all of the devices in the mesh) and causesthe wakeup transmitter to send a wakeup frame containing the address orwakeup pattern of the next station. When the mesh network node receivesan acknowledgement to the wakeup sequence from the remote station (whichwas sent using a high speed protocol such as WLAN, Bluetooth, Zigbee),the mesh network node transmits one or more high speed protocol (WLAN,Bluetooth, Zigbee) frames to the destination station.

Either periodically with the transmission of advertising sequencepatterns (received by all stations), or alternatively when the mesh nodewakeup receiver receives a wakeup sequence from an adjacent station, thewakeup receiver checks to see that the transmitting station is in acurrent list of stations, and either adds the adjacent station to thelist of stations or updates an existing entry for that adjacent station,with the list of stations organized by a remote station identifier.Optionally, the transmitting station includes a metric indicating itsdistance from a gateway, its state of charge (SOC), and any otherinformation which is used in the node's own advertisements to othernodes for its distance to the gateway and SOC information for computingroute metrics, for the case of the gateway distance, by adding one tothe number of hops to the gateway.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows the positions of a gateway station and a plurality ofstations in either a plan view without barriers, or alternatively anelevation view of stations in a building.

FIG. 1B shows block diagram of a plurality of stations in a meshnetwork.

FIGS. 2A and 2B show the list of stations maintained by each of thenodes in FIG. 1B.

FIG. 3 shows a block diagram of a mesh node.

FIG. 4 shows waveforms for the sequence of transmissions by a wake-uptransmitter of a node of FIG. 3 .

FIGS. 4A, 4B, and 4C show waveforms for alternate wakeup transmitsequences.

FIG. 5A shows a time sequence diagram for a first mesh stationtransmitting to a second mesh station.

FIG. 5B shows a time sequence for data passing through the mesh networkof FIG. 1B.

FIGS. 6A, 6B, 6C, 6D, 6E, 6F, and 6G show timing diagrams for themovement of data through three stations.

FIG. 7 shows a flowchart for a wakeup receiver process.

FIG. 8 shows a flowchart for a wakeup transmitter process.

FIG. 9 shows a flowchart for a mesh receiver process.

FIG. 10A shows a perspective view of an arrangement of mesh nodes forpackage delivery and tracking.

FIG. 10A-1 shows a plan view of an example residence of FIG. 10A.

FIG. 10B shows a perspective view of a residential neighborhood withconsumer tags for monitoring and tracking items.

FIG. 10C shows a perspective view of a residential neighborhood withinfrastructure tags for smart city monitoring of utilities andresidential items.

FIG. 10D shows a plan view of a residence in a smart city configurationof the invention.

FIG. 10E shows a plan view of several residences in a mesh network.

FIG. 11A shows a timing diagram for an example hierarchical first andsecond wakeup sequence.

FIG. 11B shows a table of false alarm rates for the first and secondwakeup sequence of FIG. 11A.

FIG. 12 shows an example block diagram for a wake-up receiver accordingto an embodiment of the present invention.

FIG. 12A shows a block diagram of a secure wakeup pattern generator foruse in a transmitter and receiver.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1B shows an example mesh network formed from mesh devices of thepresent invention. Each of the mesh stations M1 102, M2 104, M3 106, M4108, M5 110, M6 112, M7 114, M8 116 is shown as 300 of FIG. 3 , whichincludes wakeup receive processor 304 for waking up the mesh receiveprocessor 308 from an RF sequence, and transmit processor 302, which isoperative in a wakeup transmit mode for sending a wakeup sequence formedfrom keyed RF patterns (or alternatively from entire WLAN packets) as asequence of “1” values for an entire packet or RF duration or “0” whennot transmitting for an equal interval of time, sending this sequence tosurrounding mesh stations as RF. In a mesh transmit mode, the transmitprocessor 302 may transmit ACK and data packets as IEEE 802.11ac, IEEE802.11n, IEEE 802.11g, or any IEEE 802.11 frame format, or it maytransmit ACK and data packets as Zigbee, or it may transmit ack and datapackets as Bluetooth packets, either as BLE or BLR packets.

Each station maintains a list of adjacent stations as entries, eachentry shown with the associated link for reference, the entry includinga remote station identifier, a signal strength for that remote station,a State of Charge (SOC) indicating the remaining battery life, and agateway path number (GPn) showing how many hops to a remote gateway.From these entries, a metric may be formed which indicates a bestrouting path which also ensures that all of the mesh station batteriesare uniformly depleted over the life of the mesh stations. FIGS. 2A and2B show an example list of entries for each station M1, M2, M3, M4, M5,M6, M7, and M8. Upon receipt of a wakeup frame from an adjacent meshstation, the receiving station wakes up, optionally sets itself to aparticular wireless protocol (802.11, Zigbee, Bluetooth) on a specifiedfrequency channel or temporal channel, sends an ACK packet to the wakeuptransmitting station using the selected protocol and channel whichoptionally accompanied the wakeup sequence, enables its mesh receiverfor the selected protocol and channel, receives the transmitted framesfrom the sending mesh station, places them into a queue, and either goesback to sleep, or sends the wake-up sequence directed to the intendednext mesh station according to routing instructions it derives from itsown set of route tables and any address information in the packets itreceives.

FIG. 4 shows a timing diagram for a mesh transmit protocol according toan example of the invention. Each mesh device M1 through M8 operatesautonomously from any other mesh device. As previously described forFIG. 3 , each mesh device has a wakeup transmitter for sending a wakeuppattern to surrounding mesh devices, the wakeup message comprising awakeup sequence of 1s and 0s formed by a packet and a packet gap,respectively, or keyed RF, either one of which is optionally followed bya command for establishing protocol, channel, and any other parametersfor the communications which follow using the mesh transmitter and meshreceiver, starting with the mesh transmitter sending an ACK to thetransmitting station in response to its wakeup sequence.

At a time when a mesh device has data to transmit to another station,the mesh device wakeup transmitter sends a wakeup sequence, using anentire packet of length n to form a “1” value and not transmittinganything for an equal duration of time to form a “0” value. By sending asequence of packets (“1” value) and gaps (“0” value), the wakeupsequence may be sent, which may optionally be only a wakeup sequenceuniversal to all mesh stations (for example so that each station canestablish or refresh its table of neighbor stations), or the wakeupsequence may contain a first segment and second segment of differentdata rates, or a command may optionally follow the wakeup sequence thatestablishes the protocol and channels in use thereafter, as before.

In a hierarchical wakeup sequence, the wakeup sequence may comprise twoor more wakeup sequences having different bit interval timings, forexample the wakeup sequence may comprise a low rate first wakeupsequence followed by a higher rate wakeup sequence, each formed from asequence of packets and gaps as previously described, each 1 or 0 of asubsequent wakeup sequence having a 1 or 0 bit duration t of t/2, t/4,t/8, or t/16 compared to the 1 or 0 of a previous sequence. For example,the wakeup sequence could be 2 ms overall, as 8 bits in 1 ms followed by64 bits in 1 ms. In another example of the hierarchical wakeup sequence,the first wakeup sequence may be a universal sequence of is and 0s forthe first wakeup segment followed by a higher rate second wakeupsequence where the second wakeup sequence includes an address specificto a particular destination mesh station. The advantage of thehierarchical wakeup sequence is that a receiving mesh device may sampleat a comparatively low rate until it senses that a mesh station wishesto transmit, thereafter examining the second wakeup segment at a highersampling rate to determine whether its address is specified in thesecond wakeup sequence and that it should awaken. The hierarchicalapproach for wakeup sequences has power savings advantages overoperating at a high sample rate at all times. The wakeup sequences maybe transmitted by a mesh station at regular intervals, such as once persecond or once per 0.1 second, or adjusted dynamically to match the rateof traffic or utilization.

FIG. 11A shows an example hierarchical wakeup sequence where, followingchannel noise 1107, a first wakeup sequence is received which is 1 mslong, comprised of 8 bits transmitted at a rate 125 us per bit and withan first sequence false alarm rate (FAR) of 10% over the 8 bit sequence,meaning that the incoming pattern is cross-correlated to form across-correlation sum which is compared to a threshold corr_threshold.In this example, the first 8 bit wakeup sequence 1108 may becross-correlated with a universal 8 bit wakeup pattern, the crosscorrelation generating a +1 for each bit match and a 0 for eachmismatch, with the result at the end of the cross-correlation comparedto the corr_threshold to generate a trigger which tells the wakeupprocessor to continue sampling the second 1 ms, but using an 8× highersample rate (and accordingly higher power consumption). The initialsample rate set to 125 us has advantageously low current draw, whereasthe higher sample rate and higher current draw is only incurred when thefirst sequence cross-correlation threshold is exceeded, with thethreshold set to an example 10% FAR (rate of false detection of firstwakeup sequence). The threshold corr_threshold may be varied accordingto desired system performance to higher or lower false alarm rates. Ifthe first wakeup sequence does not match the pattern stored by thedevice, the device continues to sample at the 1 ms rate until it doesfind a match. The current consumption during the time searching for thematching 8 bit sequence has an advantageously low current consumption ofjust 1 uA, and the first 8 bit sequence 1108 may be a common patternrecognized by all devices. The second sequence 1110 is also 1 ms induration, transmitted as 64 bits at 15.6 us per bit, resulting in 8× thepower consumption during the second wakeup sequence at 8 uA. If thesecond wakeup sequence does not match the wakeup pattern (which mayinclude the device-specific address or multi-cast address), the devicereturns to the lower sample rate of the first wakeup sequence search.Accordingly, the 64 bits of the second sequence have a low false alarmrate of 10⁻⁸, ensuring that when only 20% of the wakeup sequence (firstand second sequences) are directed to a particular station the currentconsumption for that station is 1 uA 80% of the time and 8 uA for 20% ofthe time, resulting in an average current of 2.6 uA. This is asignificant improvement over the case where a single wakeup pattern of64 bits is used, resulting in a current draw of 8 uA for the wakeupsequence. In one example hierarchical embodiment, the first wakeupsequence is 8 bits in 1 ms, and does not include a pseudo-randomsequence as described in U.S. Pat. No. 9,477,292, which is incorporatedin its entirety by reference. In the example embodiment, the secondwakeup sequence is 64 bits in length and at least part of the secondwakeup sequence is time encrypted such that a sequence of possible nextpseudo-random sequences are autocorrelated for wakeup. Additionally, thesecond wakeup sequence may include a unicast address for a singledevice, a broadcast address for several devices, and the second wakeupsequence may be followed by additional commands including a channelassignment or protocol assignment.

As the incoming wakeup pattern bit rate is very low, the wakeup RFreceiver may be powered on and off at a rate of the bit rate of the bitsequence being sampled. For the present example of 8 bits in 1 msfollowed by 64 bits in 1 ms, the receiver may repetitively power on andoff at a rate of 8 Khz during the first interval and 64 Khz during thesecond interval, each sample used in forming a running cross-correlationresult with the wakeup-pattern, as described in U.S. Pat. No. 9,477,292.

On the wake-up pattern transmission as it relates to prior art AccessPoints (AP) and other equipment which predates the present invention, aparticular advantage of the wakeup-transmitter mode 302 is that anyexisting prior art WiFi device which is able to be firmware upgraded canform wake-up packets according to the present invention, since WLANpackets with arbitrary data contents can be formed into a wakeupsequence easily, with the packet length selected to form the “1” patternand non-transmission forming the “0” pattern of the first and secondwakeup sequence, and both the mesh device and the prior art WiFi deviceare already fully capable of communication once the mesh device is awakeusing prior art WLAN methods and standards. In this manner, the priorart WLAN device can easily be firmware upgraded to transmit the wakeupsequence as a series of packets and packet gaps.

The waveform 402 of FIG. 4 shows an example wakeup sequence, where thewakeup sequence is transmitted at regular intervals for mesh nodeadvertisements, such as from 404 to 406, from 408 to 410, and from 412to 414, or on a demand basis when a node has data to transmit throughthe mesh. Alternatively, the wakeup transmissions may occur at aninfrequent rate, and thereafter on a demand basis when data has beenreceived which is to be forwarded to a subsequent mesh station.

An expanded view of a wakeup sequence 404 to 406 is shown in FIG. 4Awaveform 420, where each “1” value 422 and 426, for example, is formedby an entire WLAN packet (from preamble through CRC), and each “0” value424 is formed by having the transmitter remain silent for an equalduration of time as the “1” value packet duration of time, with the “1”values and “0” values each having a uniform time length in eachsequence, as was previously described. Waveform 420 shows a singlewakeup sequence 434, where the wakeup sequence is a unique address for areceiving station (for a unicast transmission) or is a common addressshared by all stations (for a broadcast message).

FIG. 4B waveform 440 shows a hierarchical wake-up sequence embodiment,where the wakeup sequence 443 comprises a first wakeup sequence 442followed by a higher rate second wakeup sequence 456. Optional commands458 may follow for protocol and channel selection, as previouslydescribed.

FIG. 4C shows another variation, where the wakeup sequence 469 may beidentical for all mesh stations and followed optionally by a deviceaddress (unicast or broadcast) 478, and also optionally include commands480.

FIG. 5A shows a timing diagram for mesh stations A 502 sending data tomesh station B 504 using a WLAN protocol and predefined channelassignments. Station A 502 starts by sending a wakeup sequence (1s and0s as WLAN packet/silence from transmitter 302 of FIG. 3 ) tosurrounding stations. Station B has an address which corresponds to theparticular wakeup sequence transmitted by station A 502, and responds bywaking up during interval 508, activates its mesh transmitter for WLANpackets, and transmits an acknowledgment 510 to station A, which hasalso awoken to receive the acknowledgement as a WLAN packet. The meshstation 502 transmits packets 512, which are acknowledged 514 by stationB 504, and station A goes back to sleep in a low-power mode, respondingonly to wakeup packets it may receive from surrounding stations wherethe wakeup packet is formed to include the address of STN A.

FIG. 5B shows a timing diagram for mesh communications, where thesequence of figure aA repeats for each event for station M8 520transmitting packets to GW1 528 through the mesh. The sequence of wakeupsequence 530, WLAN ACK 532, WLAN data 534, and WLAN ACK 536 complete thetransmission from mesh station M8 to M5 522. M5 522, before or aftersending ACK 536 to M8, sends a wakeup packet 538 to M2, which initiatesthe same WLAN ACK sequence of 540, TX DATA 542, and WLAN ACK 544 intransferring from M5 to M2. The transfer from M2 to M1 similarly occursstarting with wakeup sequence 546, and mesh transmit 550 sends highspeed data from M2 to M1 using any of the protocols as described. Datafrom mesh station M1 526 to gateway 528 is accomplished in the finalstep where the gateway 528 may be awaken with packet 554, which isacknowledged as a WLAN packet 556, and the data is transmitted 558 andacknowledged 560.

FIG. 6A to 6G shows a time sequence corresponding to the movement ofdata from M8 to M5 and from M5 to M2 of FIG. 5B. Waveform 602 shows thewakeup sequence sent to M5 from 620 to 622 and received by M5 aswaveform 604 showing the receive event from 624 to 626 of the 1 and 0wakeup sequence, which is acked from time 628 to 630, followed by datatransmission from 632 to 634, which the remote station acks from 646 to648, which initiates station M5 waking M2 from 640-642, ending thecanonical cycle of wakeup, ack, data transmission, ack, and next stationwakeup shown by the transactions of 601 (vertical axis).

In one example, the mesh network may be configured for operation as alocal mesh (such as the package delivery example of FIG. 10A where themesh station of the package is coupled over a short distance to a nearbywarehouse access point 1027, drone mesh station, delivery truck meshstation or residence mesh station. In another example, the mesh networkmay be configured for longer long range connections, such as when usedas a neighborhood mesh of FIG. 10B or smart city of 10C.

For a local mesh, the wakeup receiver requires receive sensitivitiessimilar to those used in WLAN IEEE Standard 802.11n, 802.11ac, ZigBee orBluetooth, with receiver sensitivity for an approximate 100-110 dB linkbudget, which implies approximately 10-20 dBm transmit power andapproximately −85 to −95 dBm receiver sensitivity. The distance betweenstations in each hop of a local mesh is typically 30 m-200 m dependingon path obstacles. In a neighborhood mesh with longer link distances,greater sensitivities similar to WLAN IEEE 802.11ah or Bluetooth LongRange protocol are used of approximately 125-140 dB link budget,translating into a transmit power of 10-25 dBm and −105 to −120 dBmreceiver sensitivity. Using these metrics, each hop in neighborhood meshcan reach 200 m to 2 km typically, depending on the multi-pathreflection and path obstacles.

Additionally, for a neighborhood mesh, the receiver sensitivityrequirement is greater than the local mesh configuration. The increasedreceiver sensitivity for the neighborhood mesh is achieved by using areceiver with lower noise figure, greater antenna gain, and narrowerreceiver bandwidth of approximately 100 KHz to 400 KHz whereas thewakeup receiver operating on a local mesh configuration can have relaxedreceive bandwidth of approximately 2 MHz to 10 MHz. For meshcommunications, the receive bandwidth is typically achieved by mixingthe received RF to an intermediate frequency (IF) and filtering thatfrequency, then baseband converting the IF. In the case of the wakeupreceiver, it is sufficient for the wakeup receiver to convert theincoming RF to an IF that is approximately 2 Mhz to 10 Mhz offset fromthe carrier frequency for local mesh communications, or 500 Hkz forneighborhood mesh communications, where the carrier is typically 2.4 Ghzor 5 Ghz for 802.11. In either method, the output of the IF mixer isfiltered to the bandwidths described and envelope detected such as witha diode or baseband mixer and filter.

FIG. 12 shows an example block diagram for a wakeup receiver 1204according to the present invention. Wireless wakeup sequences arereceived on antenna 1202 according to keyed on/off patterns of RF power,which are received and amplified 1206 and applied to mixer 1208, whichmixes with a local oscillator which is offset by a frequency such asapproximately 100 Khz-400 Khz for a neighborhood (long range) receiver,or 2 Mhz-10 Mhz for a local (short range) receiver, and is filtered1212, envelope detected 1214, threshold detected to produce and store abinary pattern, which is correlated and accumulated 1218-1. Thecorrelator will produce a peak accumulated value at the point where theincoming wakeup sequence from threshold detector 1216 matches the wakeuppattern stored in key 1220-1, with an example 8 Khz sample rate, whichwill trigger threshold detector 1222-1, signaling to the controller tostart sampling at the rate of the second wakeup sequence (64 Khz for 64bits in 1 ms). As an additional power savings, the processing circuitry1206, 1208, 1210, 1212, 1214, 1216 are powered up only long enough totake a sample to provide to the correlator 1218-1, each componentpowered up a settling time prior to the sample time. It should also benoted that because the IF filter frequency 1212 has a longer responsetime for neighborhood mesh applications than local mesh applications,the IF filter is programmed by the controller 1226 accordingly, and thepower-on duty cycle 1228 is slightly increased to compensate for thelonger settling time required in neighborhood mesh wakeup configurationthan local mesh wakeup configurations. In one example of the invention,the sample rate (and power-up rate of the processing elements of FIG. 12) is the same as the bit rate. In another example of the invention, thesamples are taken as “even” samples at 1× the wakeup pattern bit rateand as “odd” samples at 1× the wakeup pattern bit rate, shifted 180degrees to the midpoint of the “even” samples. In this manner, theproblem of sampling transitions is avoided.

For a wakeup pattern which is secured by a random sequence derived froma time for secure wake-up sequences, multiple correlators and keys areused 1218-1/1220-1, 1218-2/1220-2, 1218-3/1220-3, one for each possiblekey to cover the case of temporal boundary key changes. FIG. 12A showsan example of key generation 1250 where each matching key is securelygenerated at both the transmitting station and each receiving meshstation. A root of trust 1252 secures that the shared public key 1254 isauthentic, and public key 1254, private key 1256 which is securely givento all stations during a commissioning event. The commissioning eventmay be the assignment of a hard-coded secret key burned into the deviceat time of manufacturing of all mesh station devices, or by using anassigned secret key at a configuration event. The public and privatekey, as well as a time clock 1258 are input to a one-way function 1260which generates an output code from which it is difficult to extract thealgorithm which produced it. The one-way function may be a hash, or itmay be any function for which it is difficult to find an inversefunction, thereby preventing the extraction of the private key orfunction for use in spoofing the network from knowledge gained byexamination of the behavior of the one-way function 1260 or its outputsequences. The output of function 1260 is used to update at least one offirst key 1220-1, second key 1220-2, or third key 1220-3 used by thereceive wake-up correlator. Typically, a transmitter will use a firsttime-varying key for unicast transmission, and a second time-varying keyfor multi-cast transmission, or a single key may be used with theunicast/multicast distinction provided by a follow-on field, as wasdescribed previously. The receiver keys 1220-1, 1220-2, and 1220-3 arethe wakeup sequence patterns used by the autocorrelator as described forFIG. 12 and also used as the wakeup sequence sent by the wake-uptransmitter. When the secure key changes because of a time increment,the transmitter protocol completes the current secure key transmissionbefore changing to a different secure transmit key, so the incomingsequence of correlation is allowed to complete before the controller1226 provides a new secure key, and it only need change one secure keyat a time at each secure key update event.

Using the hierarchical first wakeup pattern and the second wakeuppattern, it is possible to get longer bit times without sacrificingfalse alarm rate. The first wakeup sequence primarily determines bitduration and hence the wakeup receiver sampling rate, and the secondwakeup sequence of the hierarchy primarily determines the false alarmrate. For this reason, in neighborhood meshes with potentially longerlinks and lower SNR, the use of the hierarchical first and second wakeupsequence is more important to minimize the average power of the wakeupreceiver to less than 10 uA while retaining the mesh hop latency to <2ms in the case where the wakeup pattern length is approximately 2 ms intotal length of first sequence and second sequence.

It was previously noted that for the prior art operating at the 10 uAlevel, Bluetooth was capable of 5.4 MB/day and WiFi was capable of 18MB/day. However, using the prior art Bluetooth connection at 1 ms/500 mswould result in a latency of 2 seconds per hop, and Wifi at 1/6000 mswould result in latency of 24 seconds per hop, whereas the latency ofthe present invention for a first and second wakeup sequence of 1 mseach results in a latency of well less than 3 ms per hop, providing alatency improvement of ˜100× for Bluetooth and ˜1000× for WiFi.

FIG. 7 shows a process flow for a wakeup receiver using the hierarchicalwakeup sequence. The wakeup receiver 304 of FIG. 3 may detect RF energy704 by rectification of incoming RF energy against a threshold forultra-low power consumption (the rectifier is passive and the thresholddetector requires minimal power), by mixing incoming RF to baseband withamplification and detection to detect the envelope of the RF, which ismore sensitive while consuming a miniscule amount of current which isonly slightly greater than rectification. When RF packet energy isdetected by one of these methods in step 704, a low rate preambledetection process occurs 706 for the duration corresponding to 440 ofFIG. 4 , optionally followed by a high rate preamble detection process708 (for hierarchical wakeup processing) corresponding to 456 of FIG. 4. When the wakeup sequence corresponds to the unicast wakeup sequence ofa particular mesh receiver, the corresponding mesh receiver wakes up710, enables the mesh station transmitter 302 of FIG. 3 to acknowledgethe wakeup (using a mesh WLAN packet), receives mesh packets from theadjacent station, and sends an acknowledgement, thereafter eitherreturning to sleep 712 and waiting for the next wakeup packet 704, orsending its own wakeup packet to the next hop station, each stationrepeating the hop sequence until the destination station or gateway isreached. Steps 710 and 712 are shown in dashed lines for reference, asthese functions are performed by the mesh transmitter and receiver, andnot the wakeup receiver of FIG. 7 . Additionally, station RSSI data andother information as described in the tables of FIGS. 2A and 2B aremaintained for stations which have previously transmitted mesh data tothe wakeup receiver, which may be periodically accomplished by havingeach station transmit a broadcast packet so that all adjacent stationsmay wake up and update their respective station tables as shown in FIGS.2A and 2B.

The mesh station of FIG. 3 shows the transmit processor 302 aspreviously described, which is capable of transmitting keyed wakeupsequences by keying the RF transmitter on and off, or by using entirepackets which may be used to form wakeup sequences, or alternatively,using packets for particular protocols including 802.11 family ofwireless packets, Zigbee packets, or Bluetooth packets. Additionally,the transmit on/off 1/0 sequences may be formed by having the transmitprocessor send a long baseband packet to be mixed to a carrier frequencyand transmitted, with the on/off keying performed by turning on and offany of: the RF amplifier, the mixer, or any other RF chain componentswhich amplify or couple the RF to the antenna, thereby forming thedesired 1/0 pattern of the wakeup sequence. The wake receiver process304 compares an incoming wakeup sequence to a station-specific receiveraddress and a broadcast address, taking the device out of sleep modewhen a match is made. Optionally, the wake-up processor 304 alsoprocesses a command such as an instruction to enable the mesh station tooperation with a particular protocol or channel. The mesh receiver 308is able to receive and process the specified protocol type and frequencychannel as specified in the optional command part of the wakeup sequenceas was described in FIG. 4 . For certain applications, it may bedesirable for the mesh station 300 to determine a location via GPS, ordetermine a location using a WiFi protocol, or to detect movement usingan accelerometer as provided by location and motion functions 314. AnIPv6 subnet router 316 is provided for forming and operating on thesubnet of mesh stations, and the route/neighbor table 318 is providedfor local subnet routing based on providing SOC metrics so that thestations are equally taxed for power consumption over the life of thelocal battery. The route tables may also include entries indicating aroute cost or available bandwidth so that uniform utilization of themesh stations may occur by including route utilization information inthe route tables so these are considered in the route metric.

FIG. 8 shows a process flow for the transmitter in a mesh datatransmission mode, which starts with forming the wakeup pattern of 1sand 0s using entire WLAN packets or keyed RF in step 802 correspondingto the wakeup-pattern of a unicast target device. The transmitter mayemit a “self-CTS” on the channel using a prior art method to preventother stations from transmitting during the interval the transmitter issending the wakeup sequence. After transmission of the self-CTS andwakeup pattern, if an ACK is not received, a retransmission step 802 isperformed, or if the ACK is received, transmitting mesh data using thespecified protocol 806, and finally either receiving an ACK andreturning to step 802 when the next transmit wakeup even occurs, orretransmitting the previous data 806 if an ACK was not received.

FIG. 8 may be understood for periodic advertising by transmitting abroadcast sequence for which all mesh stations are responsive. In theadvertising mode, broadcast wake-up sequences are periodicallytransmitted to surrounding mesh stations (such as with the hierarchicalwakeup patterns of waveform 440), with the first and second sequencegeneration and transmission is called in step 802, which generates thefirst sequence 440 and optionally second sequence 442 for thehierarchical wakeup pattern. The advertisements are infrequentlytransmitted 802 for the purpose of allowing each device to update itsstation table 318 of FIG. 3 , with the ACK 804 being optional, and nodata being transmitted 806 or received 808.

FIG. 9 shows the process for a mesh receiver, which is only powered onreceipt of a wake-up frame identifying the present mesh as destination,such as by use of a unique wakeup pattern for that station. The meshreceiver receives the packets, acks them (as shown in series 601 of FIG.6B-6E), and initiates the transmit sequence (wakeup, ack, transmit data,ack, sleep) in step 904.

In another aspect of the invention using hierarchical wakeup sequences,the first sequence or the second sequence uses a pattern which variesover time and is known to all of the devices in a local mesh. One typeof security exploit the wake-up receiver is susceptible to is an exploitwhere a listening hostile device learns the first wakeup sequence andsecond wakeup sequence and launches a “battery attack” on the meshdevices by repetitively sending wakeup sequences and causing the meshreceivers to draw excess current in the wake-up state for non-existentpackets. This may be addressed by providing a series of time-stampedwakeup pattern, such as by using a time-synchronized series of uniquewake-up patterns known only to the mesh devices, for example where thepublic (shared) key is sent to all nodes in a broadcast command from aninitial state. In one example of the invention, the first wake-upsequence is a pseudo-random sequence known to the mesh transmitters andmesh wake-up receivers. However, this may not be desirable since theobjective of the first wakeup sequence is low power and is typically ashort sequence. In another embodiment of the invention, the secondwakeup sequence is longer and is used for the time-stamped wakeuppattern, as the receiver is subsequently enabled after the second wakeupsequence is a match for a particular mesh device.

FIG. 10A shows a perspective view of an example package tracking anddelivery system using the present invention. In one example of theinvention, a distribution warehouse 1001 as one or more warehouse accesspoint nodes 1027 for communication with mesh nodes inside the warehouse,and with a transit point node 1029 detecting that packages which areoutfitted with mesh devices have left the warehouse for distribution tocustomers. The packages may be delivered by drones (1002, 1004, 1006,1008, 1010, and 1022, and trucks 1030 and 1032, each drone or truckhaving a local mesh node, a GPS or other location tracking system, andan LTE wireless communication system which transmits location andpackage status to a remote tracking server such as through the LTEwireless network 1007. The drone wireless stations 1002, 1004, 1006,1008, 1010, 1022, are similarly outfitted with GPS or location trackingsystem, a mesh node for communication with the package or package meshnodes they transport, and an LTE wireless system for communication withan LTE network 1007. A delivered package 1015 may be detected by aresidential mesh or access point in residence 1014 for confirmingdelivery to the resident apart from the notification provided by thedelivery drone or truck. Alternatively, the drone wireless stations1002, 1006, 1008, 1010, 1022 and truck wireless stations 1030, and 1032each may locally form a separate mesh with each other when in proximity,each station in communication with at least one adjacent station capableof providing updates through the LTE network 1007 or a mesh gateway oraccess point back to the distribution warehouse 1001 or other point ofaccess, thereby communicating data about package deliveries and deliverystatus to the various delivery destination customers 1012, 1014, 1016,1018, 1020, 1024, 1026, and 1028. In another alternative embodiment, thepackages which are outfitted with mesh nodes transmit locationinformation to each other, which is transmitted back to the warehouse1001. As is clear from the number of moving mesh stations of FIG. 10A,it may be desirable for at least one mesh station to have anaccelerometer, GPS receiver, or WiFi location information 314 forindicating when it is on the move, so that it can rebuild its databaseof neighbor mesh nodes, as well as periodically provide location updatesto the central warehouse 1001 which provides updates to the variouspackage recipients.

FIG. 10B shows a neighborhood tag tracking example of the mesh networkwhere a local mesh is formed by stations within a particular household,or alternatively, a mesh network is formed by mesh stations in houses1050, 1052, 1054, 1056, 1058, 1062, and 1064. Pets 1074, and 1062 in theneighborhood may wander within established boundaries determined by thefixed station locations, such that when an animal moves beyond itsestablished boundary (based on RSSI, GPS, signal strength to one or morelocations, or presentation near an unexpected remote mesh station), analarm may be sent to its owner, accompanied by the current location, ora continuously updated series of locations for providing a movementvector. In one example, a trigger for the sending of a location messageoccurs when the mesh network examining known stations and ReceivedSignal Strength Indicator (RSSI) associated with the animal's normalrange of movement detects proximity to a previously unknown mesh stationafter losing contact with a known mesh station. For example, meshstations 1058 or 1060 may be known for pet 1062 in a backyard adjacentto mesh station 1058, whereas lost pet 1074 may be associated withbackyard 1056, such that when station 1056 loses communication with pet1074, or the receiving gateway receives information that pet 1074 is notin communication with 1056 but is in communication with 1050 and 1052,an alert indicating the location of the pet may be sent to the owner.

FIG. 10C shows a “smart city” example, where the mesh nodes of eachhousehold 1050, 1052, 1056, 1058 1060, and 1064 are in localcommunication with aspects of associated city infrastructure, and cityservices provided through a mesh network which is part of signposts 10661068, and 1070, and light pole mesh stations 1075 and 1077. Other mobileor fixed mesh stations may be placed where needed for communicating withother mesh stations which may momentarily present themselves andexchange information.

FIG. 10D shows an example home 1064 from FIG. 10C, which may include aresidential home security or home infrastructure information system. Acentral access point 1080 may be in communication with mesh stations1081 for reporting electric utility measurement, garbage can meshstation 1082 for confirming refuse pickup, car 1084 mesh device 1083 forvehicle security, or front door mesh device 1086, which may detectdelivered packages. Additional mesh nodes may be dedicated to securityalarm systems, motion detectors, furnace and HVAC control systems,security camera systems, and other devices as may be used to providemore efficient use of energy and increased security.

FIG. 10E shows an example of a sparse mesh network, where only residence1095 has a gateway 1093, but this and the other residences 1095A, 1095B,and 1095C each have meshed network-capable devices, such as refrigerator1091A, 1091B, 1092C, washer 1092A, 1092B, 1092C, dryer 1094A, 1094B,1094C, dishwasher 1090A, 1090B, 1090C, and other mesh devices which areenabled with Internet of Things (IoT) capable hardware. An ongoing issuein these “smart” appliances is that setup is required for them to beprovisioned to a network, which is the prior art process of “joining” or“associating” to a wireless network, requiring configuring the IoTdevice, which often requires a computer and knowledge of the accesspoint SSID, network key and network key type. Accordingly, few consumerswith such “smart” appliances have the patience or time to connect themto a network, and service codes and the like which may otherwise bereadable electronically require a service visit to read the repair codethe device is attempting to provide. In the example of FIG. 10E, onlyone residence 1095A has a wireless gateway 1093A, and perhaps onlyrefrigerator 1091A is configured to use the gateway, or perhaps noappliances are configured to use it, but gateway 1093 is mesh-enabledaccording to the present invention. In the mesh network of FIG. 10E, notonly may the other appliances 1090A, 1092A, and 1094A connect to theinternet using the mesh station of refrigerator 1091A to reach gateway1093A, but the appliances in surrounding residences 1095B and 1095C mayalso join this mesh network to send their data through the mesh todevice 1091A, or to access point router 1093A, and as long as a chain oftwo stations in receiving range of each other can be formed for each ofthe mesh nodes, a network path will be available for every appliance ormesh-ready device through the mesh devices to a gateway such as 1093A.

In the present specification, approximately is understood to mean to+/−12 dB for signal levels and +/−50% for distance or other linearmeasurement. The examples of the specification are set forth forunderstanding the invention, the scope of which is limited only by theclaims which follow.

We claim:
 1. A network comprising a plurality of mesh network devicesand a gateway device, each mesh network device having a wakeuptransceiver and a network transceiver; the network transceiver in asleep mode and operative to engage in high speed communications uponreceipt of a wakeup signal, the network transceiver maintaining a tablecontaining at least one entry, the at least one entry indicating anadjacent station identifier and a number of station hops to the gatewaydevice; the wakeup transceiver generating the wakeup signal upon receiptof a first bit sequence matching a first template and followed by asecond bit sequence matching a second template, the first bit sequencecomprising the presence or absence of RF energy transmitted by adifferent mesh network device, the first bit sequence having a falsealarm rate of greater than 10%, and the second bit sequence having a bitrate which is at least a factor of two greater than the bit rate of thefirst bit sequence; the network transceiver, upon wakeup, receivingpackets for forwarding to a next mesh network device, examining thetable for an adjacent station identifier having a shortest route to thegateway device; the wakeup transceiver or the network transceivertransmitting a wakeup sequence comprising a first bit sequence followedby a second bit sequence at a greater bit rate than the bit rate of thefirst bit sequence; the second bit sequence including an address of theadjacent station identifier having the shortest route to the gatewaydevice; the network transceiver, upon receipt of a wakeupacknowledgement from the next mesh network device, transmitting thepackets for forwarding.
 2. The network of claim 1 where the networktransceiver is operative to process at least one of an 802.11 packet, aBluetooth packet, or a Zigbee packet.
 3. The network of claim 1 where aduration of the second bit sequence is substantially equal to a durationof the first bit sequence.
 4. The network of claim 1 where the at leastone table entry includes a signal strength and state of charge used toform a routing metric for selection of the adjacent station.
 5. Thenetwork of claim 1 where the network transceiver is in a powerdown stateuntil receiving the wakeup signal, and returns to a powerdown stateafter transmitting the packets for forwarding.
 6. The network of claim 1where at least one of the first bit sequence or the second bit sequenceincludes a command identifying at least one of a protocol type or achannel for subsequent operations by the network transceiver.
 7. Thenetwork of claim 1 where at least one of the first bit sequence or thesecond bit sequence periodically changes according to a temporal patternknown to both a transmitter of the wakeup transceiver of the differentmesh network device and also to a receiver of the wakeup transceiver. 8.A process for mesh communications between a plurality of mesh networkdevices and a gateway device, each mesh network device comprising awakeup transceiver and a network transceiver which is asleep until itreceives a wakeup signal from the wakeup transceiver, the networktransceiver maintaining a table of entries, each entry comprising astation identifier and a number of hops for the station identifier tothe gateway device, the process comprising: the wakeup transceiverreceiving a first bit sequence, each bit of the first bit sequenceindicating the presence or absence of RF energy, the wakeup transceivercomparing the first bit sequence to a first template and upon a match,the wakeup transceiver thereafter comparing a second bit sequence to asecond template, the second bit sequence at a second bit rate greaterthan the first bit rate, the first bit sequence having a false alarmrate in excess of 10%; upon a match of the second bit sequence to thesecond template, the wakeup transceiver asserting a wakeup signal to thenetwork transceiver; the network transceiver transmitting anacknowledgment to a mesh network device transmitting the first bitsequence and second bit sequence; the network transceiver thereafterreceiving at least one packet of data from the mesh network devicetransmitting the first bit sequence and second bit sequence; the networktransceiver thereafter identifying a next recipient of the at least onepacket of data based on an entry in the table identifying a station witha minimum number of hops to the gateway device or state of charge (SOC),and causing the wakeup transceiver to transmit a wakeup signal to theidentified station based on the number of hops or the state of charge.9. The process of claim 8 where the network transceiver receives the atleast one packet of data and places it into a receive queue, the wakeuptransceiver thereafter sending a wakeup sequence to a different meshnetwork device; the network transceiver, after receiving anacknowledgement of the wakeup sequence from the different mesh networkdevice identified by the received at least one packet, transmitting theat least one packet in the receive queue using a wireless protocol. 10.The process of claim 8 where the next station is selected using a metricindicating a best routing path and state of charge, the metric selectedto cause each mesh station state of charge to deplete uniformly.
 11. Theprocess of claim 8 where the duration of the first bit sequence and theduration of the second bit sequence are substantially equal.
 12. Theprocess of claim 8 where the second bit sequence comprises at least oneof: a broadcast wakeup bit sequence or a unicast wakeup bit sequence.13. The process of claim 8 where the network transceiver is operative totransmit or receive at least one of an 802.11 packet, a Bluetoothpacket, or a Zigbee packet.
 14. The process of claim 8 where at leastone of the first bit sequence or the second bit sequence contains aunicast address operative to wake a single other mesh networktransceiver.
 15. The process of claim 8 where at least one of the firstbit sequence or the second bit sequence contains a broadcast addressoperative to wake a plurality of other mesh network transceivers.
 16. Amesh transceiver comprising: a wakeup transceiver further comprising: anenergy detector for generating a sequence of RF energy detection values;a first bit sequence detector comparing the sequence of RF energydetection values to a first template and generating a first match; asecond bit sequence detector comparing the sequence of RF energydetection values to a second template and generating a second match onlyif the first match is successful, and also generating a wakeup signal ifboth the first match and second match are successful; the second bitsequence at a greater bit rate than the bit rate of the first bitsequence; the first bit sequence detector having a false alarm rate of10% or more; a network transceiver further comprising: a wirelesscommunications interface for transmitting and receiving high speedwireless packets according to at least one of an 802.11 packet protocol,a Bluetooth packet protocol, or a Zigbee packet protocol; a table ofentries associating other mesh transceivers with an Received SignalStrength Indication (RSSI) value and hop count indicating the number ofstations to a gateway device; the network transceiver receiving abroadcast packet from other stations to update each associated RSSI foran associated other station.
 17. The mesh transceiver of claim 16 wherethe network transceiver receives a message for forwarding to adestination address accessible to the gateway device, the meshtransceiver forwarding the message to a mesh transceiver associated withan entry for the mesh transceiver having a minimum number of hops to thegateway device.
 18. The mesh transceiver of claim 17 where the messageis forwarded to a mesh transceiver also having an RSSI greater than athreshold value.
 19. The mesh transceiver of claim 16 where the durationof the second bit sequence is substantially the same as the duration ofthe first bit sequence.
 20. The mesh transceiver of claim 16 where thebit rate of the second sequence is a factor of 2 or 4 greater than thebit rate of the first bit sequence.